This invention relates to load carrying land vehicles and more particularly to an improved load retainer for a semitrailer structure for carrying large flat sheets of rigid material such as large sheets of flat glass.
Architectural designs for modern homes, office buildings and the like place considerable emphasis on the use of large sheets of flat glass, either as single sheets or as double insulated sheets. Transportation of large sheets of glass from the place of manufacture to the installation site is a significant cost factor affecting the overall installation costs of such sheets of glass, especially because some breakage in transit is often unavoidable. The only feasible mode of transportation for large sheets of glass is normally by truck. Various types of trucks have been designed in the past for transporting large sheets of glass. In some cases, the glass is transported in a horizontal position. However, this requires extensive crating and packing which reduces the effective payload of the truck and requires added material and labor costs for the glass. Another improved apparatus for transporting large sheets of flat glass is disclosed in my U.S. Pat. No. 3,848,917 which issued on Nov. 19, 1974. This patent discloses a generally A-shaped structure which rests on a conventional semitrailer frame. The large sheets of glass rest against the sloped sides of the A-shaped structure such that they are supported in nearly a vertical orientation. Special clamps are provided for holding the sheets of glass in place during transportation. The clamps pivot from a lower edge of the structure either to rest against the sheets of glass or to rest away from the glass. A cable arrangement is provided for holding the clamps against the glass during shipment. During loading and unloading, the cable is released and the clamps are pivoted away from the sheets of glass. However, the clamps remain attached to the structure and limit access to the glass during loading and unloading. Furthermore, no provision is made for clamping edges of the sheets of glass in place during transportation. Unrestrained edgewise movement of the sheets of glass during transportation may result in breakage.